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Many efforts have been made to develop modern wound dressings to overcome limitations of traditional ones. Smart nanocomposite hydrogels are appropriate candidates. In this work, a novel responsive nanocomposite hydrogel based on poly(vinyl alcohol)/chitosan/honey/clay was developed and evaluated as a novel wound dressing. The morphology and properties of synthesized nanocomposite hydrogels loaded with honey as a drug model were investigated. The exfoliated morphology of nanocomposite was confirmed by X‐ray diffractometry. Swelling studies were performed at 20 and 37 °C at various pH. The results showed that swelling increased as a result of temperature rise and maximum swelling occurred at a pH of 2. In vitro release of honey was also studied at the same conditions. Corresponding results indicated faster honey release rate at higher pH values. MTT results exhibited no cytotoxicity in nanocomposite hydrogel system. Investigation of antibacterial activity revealed more than 99% antibacterial activity for proposed system. In vivo results confirmed the wound healing ability of developed system. Generally, appropriate properties of proposed system made it ideal in wound dressing applications. [ABSTRACT FROM AUTHOR]

Mouse Double Minute-2 ( MDM2) is an ubiquitin ligase which is overexpressed or its promoter polymorphism has been reported in different tumours. The objective of this study was to examine the MDM2 protein expression and its promoter polymorphism in some canine tumours. Twenty specimens were collected from 20 dogs with 15 mammary gland carcinomas, 3 lymphomas, 1 transmissible venereal tumour and 1 trichoblastoma. Samples were analysed immunohistochemically using human antibody against MDM2 protein. PCR and DNA sequencing were carried out to identify MDM2 promoter polymorphism. MDM2 gene was expressed in 13 of 20 samples including 11 mammary carcinomas, 1 lymphoma and 1 trichoblastoma. We found 94% homology between canine and human sequences. Four mutations including G169C, A177G, G291T and A177G were identified in different types of breast carcinomas. An extra p53 response element was found in a mixed mammary carcinoma. [ABSTRACT FROM AUTHOR]

The main aim of this study has been to assess the spatially variability of groundwater level at different climatic periods. The study area is Saveh- Nobaran aquifer in Iran. First, using two drought indices, different climatic periods in the region including wet, normal and dry during 1993-2003 were recognized. Second, with the use of measured elevations of the water table, experimental semivariograms (spherical, exponential and Gaussian) were constructed that characterize the spatial variability of the measured groundwater levels. Groundwater levels were interpolated by four different geostatistical methods. RMSE, MAE and R2 were calculated to determine the best method. The R2 coefficient obtained from kriging, cokriging, TPSS and IDW methods were 0.95, 0.97, 0.89 and 0.83, respectively. Cokriging method was used to create groundwater-level maps, including maximum, average and minimum water levels for each climatic period. The results obtained from geostatistical analysis showed that groundwater depth varies spatially in different climatic conditions. [ABSTRACT FROM AUTHOR]

Aims We tested the hypotheses that vasoconstrictor responses to limb dependency are: (i) greater in the leg than the arm, (ii) impaired with age and (iii) not sympathetically mediated. Methods Vascular responses to limb dependency (i.e. lowering the limb from heart level to 30 cm below heart level) were determined in 17 young and 17 older adults. Indices of blood flow were obtained in the brachial and popliteal arteries (Doppler ultrasound) as well as in the cutaneous circulation (forearm and calf using laser-Doppler flowmetry). Vasoconstriction was quantified by calculating the indices of vascular resistance as height corrected mean arterial pressure/limb blood velocity or skin flux. A second group of subjects repeated the limb dependency trials after acute systemic sympathetic blockade. Results Limb dependency increased vascular resistance index in the brachial artery (∆59 ± 8%; P < 0.05) and popliteal artery (∆99 ± 10%; P < 0.05 for change in heart level and brachial vs. popliteal) of young and older adults (∆60 + 9% brachial and ∆61 ± 7% popliteal arteries; P < 0.05 for change in heart level and response in popliteal young vs. older adults). In contrast, cutaneous vasoconstrictor responses to limb dependency were similar in the forearm (∆218 ± 29% and ∆200 ± 29% for young and older adults, respectively) and calf (∆257 ± 32% and ∆236 ± 29%; all P < 0.05 from heart level) of young and older adults. Vasoconstrictor responses to limb dependency were not affected by sympathetic blockade in young or older adults. Conclusion These findings indicate that age-, limb-, and tissue-related differences may exist in the vasoconstrictor response to limb dependency in healthy humans, which are not sympathetically mediated. [ABSTRACT FROM AUTHOR]

Introduction: Simulators are increasingly used for training in echocardiography. However, there is no objective method to assess the skills acquired. Our objective was to develop and test an automated method to assess echocardiography skills., Methods: To automate the image quality evaluation, we expanded our previously developed neonatal echocardiography simulator to enable recording of images of the 26 standard cuts and process the image quality. We then compared the automated and visual methods in scoring image quality of the echocardiograms obtained by 22 trainees., Results: Each echocardiographic image representing a slice of a three-dimensional volume possesses 3 axes (X, Y, and Z) that correspond to the roll, pitch, and yaw angles of the transducer, respectively. Therefore, if the placement and orientation of the transducer are correct, the acquired image represents the appropriate cardiac window with the desired orientation in all 3 axes. The automated system gives a score of 0 if the transducer is not in the appropriate cardiac window. A score of 1, 2, or 3 is given if the image falls within the range of one, two, or three angles, respectively. There was no difference in the image quality score between automated and visual assessment methods (46.0 ± 13.0 vs 45.1 ± 14.4, P = .19). The two methods had excellent correlation (r = .95). The bias and precision were 0.9 and 8.8, respectively., Conclusions: The automated method is comparable to visual method for assessment of image quality. The automated process allows for instantaneous feedback and has the potential to standardize assessment of echocardiography skills of trainees., (© 2020 Wiley Periodicals LLC.)

Aim: High arterial carbon dioxide (PaCO2 ) and cerebral reperfusion are associated with peri/intraventricular haemorrhage. Our aim was to study the relationship between PaCO2 and cerebral blood flow (CBF) in preterm infants during postnatal transition., Methods: We prospectively studied ≤30 weeks' gestation haemodynamically stable preterm infants during the first three postnatal days (n = 21; gestational age 25.8 ± 1.4 weeks). We measured middle cerebral artery mean flow velocity (MCA-MV) as a surrogate for CBF at the time of blood gas analysis., Results: We obtained 78 PaCO2 -MCA-MV data pairs. The expected positive linear relationship between PaCO2 and MCA-MV was absent on the first postnatal day, equivocal on the second and present on the third. Using piecewise bilinear regression models, we identified PaCO2 breakpoints at 52.7 and 51.0 mmHg for postnatal days two and three, respectively., Conclusion: In haemodynamically stable preterm neonates, the expected positive linear relationship between PaCO2 and CBF may be absent on postnatal day one. On postnatal day three, and possibly day two, a PaCO2 threshold exists for this relationship, above which CBF becomes reactive to PaCO2 . We speculate that the enhanced CBF response to PaCO2 above the threshold contributes to the reperfusion injury and partly explains the association between hypercapnia and peri/intraventricular haemorrhage., (©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.)